U.S. patent application number 13/146109 was filed with the patent office on 2012-01-26 for gastric ring with a fitting rod.
This patent application is currently assigned to Compagnie Europeenne d'Etude et de Recherche de Dispositifs pour l'implantation par Laparoscopie. Invention is credited to Leo Hendrickx.
Application Number | 20120022320 13/146109 |
Document ID | / |
Family ID | 41056716 |
Filed Date | 2012-01-26 |
United States Patent
Application |
20120022320 |
Kind Code |
A1 |
Hendrickx; Leo |
January 26, 2012 |
GASTRIC RING WITH A FITTING ROD
Abstract
The invention relates to an implantable medical device (1)
comprising a flexible band (2) intended for being placed around an
organ to tightly bind the latter, said medical device being
characterised in that it includes a positioning means (10) provided
with a curved stiffening element with a rigidity greater than that
of the flexible band, said positioning means (10) being designed to
be inserted around the organ in order to substantially mark the
path for placing said flexible band (2) around said organ. The
invention can be used in the field of implantable medical
devices.
Inventors: |
Hendrickx; Leo; (Morstel,
BE) |
Assignee: |
Compagnie Europeenne d'Etude et de
Recherche de Dispositifs pour l'implantation par
Laparoscopie
Vienna
FR
|
Family ID: |
41056716 |
Appl. No.: |
13/146109 |
Filed: |
January 27, 2010 |
PCT Filed: |
January 27, 2010 |
PCT NO: |
PCT/EP2010/050946 |
371 Date: |
September 23, 2011 |
Current U.S.
Class: |
600/37 |
Current CPC
Class: |
A61F 5/005 20130101;
A61F 5/0089 20130101 |
Class at
Publication: |
600/37 |
International
Class: |
A61F 2/00 20060101
A61F002/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 28, 2009 |
FR |
0950530 |
Claims
1. Implantable medical device comprising a flexible band configured
to be placed around an organ in order to tightly bind the organ,
and a positioning device provided with a curved stiffening element
having a rigidity greater than that of the flexible band, said
positioning device being designed to be engaged around the organ in
order to substantially mark out the path along which said flexible
band is placed around said organ.
2. Medical device according to claim 1, wherein the positioning
device comprises a penetration member designed to enable the
creation of a passage in the vicinity of the organ in perforating
the tissues.
3. Medical device according to claim 2, wherein the penetration
member is formed by a smoothened or rounded tip.
4. Medical device according to claim 1, wherein the stiffening
element is plastically configurable so as to enable the adjustment
of the geometry of the positioning device before this means is
engaged around the organ.
5. Medical device according to claim 1, wherein the positioning
device is preferably laid out so that that it can be disengaged
from the vicinity of the organ in a forward motion F having the
same sense as the motion by which it is engaged around said organ
in order to position the flexible band.
6. Medical device according to claim 1, wherein the positioning
device is connected to one of the ends of the flexible band and
extends so as to protrude out of said flexible band substantially
in the longitudinal prolongation of this band.
7. Medical device according to claim 1, wherein the stiffening
element has a length between 50% and 100% of the length of the
flexible band.
8. Medical device according to claim 1, wherein the positioning
device has a cross-section smaller than that of the flexible
band.
9. Medical device according to claim 1, wherein the positioning
device is formed by a cylindrical rod of substantially constant
section.
10. Medical device according to claim 1, wherein the positioning
device comprises a rigid or semi-rigid core forming a stiffening
element, said core being housed in a sheath made of flexible
biocompatible material.
11. Medical device according to claim 1, wherein the positioning
device forms one piece with the flexible band.
12. Medical device according to claim 11, wherein the positioning
device, at the level of its junction with the flexible band, has a
preferred separation zone, designed to facilitate its separation
from the flexible band after this band has been positioned.
13. Medical device according to claim 1, wherein the positioning
device is provided with a reversible fastener designed to enable it
to be alternately connected to the device and separated from said
device.
14. Medical device according to claim 1, wherein it constitutes a
gastric ring for the treatment of obesity.
15. Medical device according to claim 1, wherein the stiffening
element has a length between 60% and 70% of the length of said
flexible band.
16. Medical device according to claim 11, wherein the preferred
separation zone includes a scored zone.
Description
[0001] The present invention pertains to the general field of
implantable medical devices and more particularly to the field of
implantable medical devices comprising a flexible band that is to
be placed around an organ in order to tightly bind it.
[0002] The present invention pertains especially to surgical ring
type devices and especially to gastric sphincters or rings designed
to be implanted around the stomach or the esophagus in the context
of a treatment for obesity.
[0003] There are known ways of treating patients affected by severe
obesity where a gastric ring is implanted in patients to surround
and tightly bind the stomach in order to limit the intake of
food.
[0004] Such rings may be placed intact around the stomach in order
to carry out a direct gastroplasty or after a "bypass" operation
during which the stomach is surgically remodeled for the creation
therein of a pouch of reduced size in order to prevent the
subsequent expansion of said pouch.
[0005] To this end, there are known ways of introducing the gastric
ring in open and relaxed form so that it can pass through the
retro-gastric tissues.
[0006] This operation, which is generally performed under
endoscopy, is nevertheless a delicate one inasmuch as a passage has
to be opened by blind dissection of the retro-gastric tissues and
then a grasping instrument has to be introduced through said
passage so as to then grasp the end of the gastric ring with said
grasping instrument and exert traction force on this ring in order
to bring back the instrument through the passage, in hauling the
ring in its train.
[0007] First of all, this sometimes requires that the practitioner
should create a relatively large-sized passage which forces him to
excessively devascularize the tissues, especially those of the
stomach, and may in certain cases provoke post-operational
complications.
[0008] Furthermore, although the engagement proper of the ring in
the retro-gastric tissues generally takes only a few minutes, the
grasping instrument must, on the contrary, be positioned well in
advance and usually must remain in place during the major part of
the operation.
[0009] Now, since this instrument has to be controlled by a
proximal portion situated outside the patient, a section of said
instrument passes constantly through the abdominal wall, via a
catheter. This transcutaneous communication is a point of leakage
through which escapes the gas used to inflate the abdominal cavity
during the operation. The operation then requires a fairly high
flow rate and/or supply pressure and leads to excess consumption of
inflating gas.
[0010] The objects assigned to the present invention are therefore
aimed at overcoming the drawbacks enumerated here above and
proposing a novel implantable medical device designed to be placed
around an organ to tightly bind this organ, this device being
particularly simple and reliable in its implantation, especially by
laparoscopy.
[0011] Another object assigned to the invention is aimed at
proposing a novel implantable medical device that facilitates the
surgical gestures needed for its implantation.
[0012] Another object assigned to the present invention is aimed at
proposing an implantable medical device that substantially reduces
the risks of per-operational accidents, as well as the trauma
suffered by the patient.
[0013] Another object assigned to the invention is aimed at
proposing a novel implantable medical device that is versatile and
capable of being adapted on a case-by-case basis to the anatomical
configuration of the patient under operation.
[0014] Another object assigned to the present invention proposes a
novel implantable medical device having high ergonomy that makes it
easier to handle by the practitioner.
[0015] Another object assigned to the invention is aimed at
proposing a novel implantable medical device that is relatively
simple and compact in its design.
[0016] Another object assigned to the invention is aimed at
proposing a novel implantable medical device having high stability
once implanted.
[0017] Finally, another object assigned to the invention is aimed
at proposing a novel implantable medical device adapted to the
treatment of obesity.
[0018] The objects assigned to the invention are achieved by means
of an implantable medical device having a flexible band that is to
be placed around an organ in order to tightly bind this organ, said
medical device being characterized in that it comprises a
positioning means provided with a curved stiffening element having
a rigidity greater than that of the flexible band, said positioning
means being designed to be engaged around the organ in order to
substantially mark out the path along which said flexible band is
placed around said organ.
[0019] Other objects, features and advantages of the invention
shall appear in greater detail from the following description as
well as by means of the appended drawings which are given purely by
way of illustration and on a non-exhaustive basis. Of these
drawings:
[0020] FIG. 1 provides an illustration, in an exploded view in
perspective, of an alternative embodiment of the implantable
medical device according to the invention.
[0021] FIG. 2 is an illustration, in a lateral view of a partial
sagittal section, of the medical device shown in FIG. 1.
[0022] FIG. 3 is an illustration, in a lateral view of a partial
sagittal section, of a second alternative embodiment of the
implantable medical device according to the invention.
[0023] The present invention generally concerns an implantable
medical device 1 comprising a flexible band 2 that is to be placed
around an organ (not shown) in order to tightly bind or grip this
organ.
[0024] Preferably, the device 1 according to the invention is
designed to be placed around an organ forming a pouch or a duct so
as to limit or reduce the section of passage of this organ.
[0025] According to one alternative embodiment, said device 1 may
be laid out to form a sphincter for regulating the blood flow
and/or for treating urinary or fecal incontinence.
[0026] However, preferably, said device 1 is a gastric ring
intended for the treatment of obesity, designed to be positioned on
the esophagus or on the stomach and especially designed to
constitute a gastric ring specifically adapted to being placed on
the stomach pouch resulting from a surgical bypass operation in
order to counter the post-operational expansion of said stomach
pouch.
[0027] Besides, although it is possible, without departing from the
framework of the invention, to envisage a case where the flexible
band 2 forms a sort of saddle designed to partially surround the
concerned organ, said flexible band 2 will preferably be long
enough to contain substantially the entire perimeter of said organ
and especially to be closed in on itself substantially at its ends
3, 4 so as to be capable of forming a closed loop surrounding the
organ.
[0028] To this end, the flexible band is preferably provided with
locking means 5, 6 designed to hold it in a closed configuration,
said locking means comprising for example male elements 5 such as
pins, intended for cooperating, for example by being clipped on,
with a corresponding female element 6 such as a sleeve.
[0029] Advantageously, the locking means are reversible to enable
the alternate closure and opening of the ring formed by the
flexible band.
[0030] It can furthermore be noted that the locking means 5, 6 can
advantageously be designed to enable an adjustment of the length of
the internal perimeter of the flexible band and may especially
comprise a succession of male elements 5 aligned in a row so as to
form several possible closing notches as illustrated in FIGS. 1 to
3.
[0031] According to one alternative embodiment not shown, the
internal face 21 of the flexible band 2, which is to come into
contact with the organ, may comprise one or more inflatable
pouches, designed to be filled with a filling fluid, such as air or
physiological serum, in order to provide for an adjustable
constriction of the organ. The present invention also pertains to
an inflatable ring, in particular a gastroplasty ring.
[0032] In particular, the device 1 may comprise an annular binding
pouch that extends substantially throughout the length of the
flexible band so as to ensure a substantially radial centripetal
compression of said organ.
[0033] The device 1 may also comprise one or more grasping tabs 7,
8 aimed at making it easier to handle said device, especially when
it is implanted and/or for enabling the actuation of the locking
means.
[0034] According to one major characteristic of the invention, the
device 1 comprises a positioning means 10 provided with a curved
stiffening element 11 which has a rigidity greater than that of the
flexible band 2, said positioning means being designed to be
engaged around the organ in order to substantially mark out the
trajectory by which said flexible band 2 is placed around said
organ.
[0035] Thus, as understood in the invention, the device 1 has an
incorporated positioning means 10 carried by the device 1 and
forming an integral part of said device during the operation and is
designed to be entirely introduced beneath the skin, for example
into the abdominal cavity, fixedly with the flexible band in such a
way that the device and more particularly the totality of its
positioning means can be handled freely inside the body in the
vicinity of the organ.
[0036] Furthermore, although it can be envisaged that the junction
of the positioning means 10 with the rest of the device permits the
captive play, of an amplitude limited by construction, of said
positioning means 10 relatively to the rest of the device 1, the
positioning means is preferably fixed to the device, for example
through the flexible band, so as to form a fixedly joined assembly
with this means, advantageously implantable and capable of being
handled as a single piece beneath the skin.
[0037] Advantageously, the positioning means 10 of the invention is
designed to be introduced into the tissues, especially the
retro-gastric tissues, so as to go around the organ until it
reappears on the visible face of this organ, enabling the
practitioner to determine and pre-visualize the position that will
be occupied by the flexible band around the organ before truly
engaging this band around the organ.
[0038] To this end, the curvature of the stiffening element 11 and
therefore that of the positioning means 10 is advantageously chosen
so as to enable said positioning means to initiate a sharp turn
around the organ until it is introduced into the tissues, thus
making it possible to easily circumvent said organ without any risk
of perforating the underlying tissues.
[0039] Naturally, the stiffening element 11 advantageously has
rigidity sufficient to enable the positioning means 10 to be
inserted and not get deformed in an untimely way when said
positioning means is drawn into the tissues and maneuvered therein
by the practitioner.
[0040] Thus, the device 1 of the invention facilitates the
introduction and placing of the flexible band 2, which in itself is
too slack to be capable of being introduced frontally into the
tissues, while allowing the device, during and after the
positioning, to preserve the flexibility needed for it to be closed
around the organ and function normally.
[0041] Preferably, the positioning means 10 comprise a penetration
means 12 designed to enable the creation of a passage in the
vicinity of the organ in perforating the tissues.
[0042] In other words, the positioning means 10 and more generally
the device 1 is advantageously adapted to being capable by itself,
when put into place, of causing incisions and/or tearing biological
tissues and especially the healthy biological tissues that surround
the organ.
[0043] The practitioner can then directly use the positioning means
10 to drill a tunnel by driving said positioning means in a
frontward motion F under stress which pushes it into this tunnel
while gradually separating the mass of tissue.
[0044] Thus, the positioning means 10 according to the invention
can advantageously open a passage by frontal penetration into the
tissues and do not necessarily require the prior making of a
suitable passage with a distinct surgical instrument.
[0045] Consequently, such a self-drilling positioning means 10
gives the device 1 a certain degree of autonomy during the
positioning and simplifies the surgeon's gestures by eliminating
the step of dissection prior to this operation phase.
[0046] Naturally, the positioning means 10 and more particularly
the stiffening element 11 is rigid enough, i.e. sufficiently
resistant to bending forces to substantially maintain its original
shape and especially the predetermined curvature of the positioning
means 10 when these means are force-inserted into the tissues to
pierce the passage.
[0047] Preferably, the penetration means 12 are formed by a
smoothened or rounded tip as illustrated in FIGS. 1 to 3.
[0048] Advantageously, an arrangement of this kind reduces
per-operational risks such as accidental perforation of the wall of
the organ and limits the extent of trauma undergone by the tissues
during the creation of the passage.
[0049] Preferably, although the stiffening element is rigid enough
to withstand especially buckling forces when it is being
introduced, said stiffening element 11 is preferably plastically
configurable so as to enable the adjustment of the geometry of the
positioning means 10 before these means are engaged around the
organ.
[0050] In other words, it is advantageously possible for the
practitioner to modify the spatial layout of the stiffening element
11 and more generally that of the positioning means 10 before its
introduction around the organ so as to give it the desired shape
and curvature given the particular anatomy of the patient being
treated.
[0051] In particular, the stiffening element 11 could
advantageously adopt and maintain a curvature that is pronounced to
a greater or lesser extent and is modifiable at leisure by the
practitioner depending on whether he or she plastically incurvates
or straightens out the positioning means 10.
[0052] Naturally, those skilled in the art will be capable of
determining the constituent materials of the stiffening element 11
as well as the geometry and the dimensions of this element, making
it possible to meet the twofold requirement of resistance to
buckling forces during penetration into the tissues and of plastic
flexibility enabling the positioning means to be modeled on site
and especially in the abdominal cavity before it is inserted behind
the organ.
[0053] Advantageously, the stiffening element 11 could be formed by
means of shape memory materials or super-elastic materials in such
a way that said stiffening element could alternately adopt a
straightened configuration, a straightened and substantially
rectilinear configuration, enabling its passage into a
transcutaneous insertion trocar device, and a curved functional
configuration. The changing from one configuration to another can
advantageously be done spontaneously as the case may be, either
under the effect of a change in temperature and especially a
heating of body temperature (for a shape memory material) or under
the effect of the relaxation of a mechanical straightening force
exerted during introduction beneath the skin by the trocar or any
unspecified accessory (for a super-elastic material).
[0054] According to a preferred characteristic illustrated in FIGS.
2 and 3, which may constitute a full-fledged invention on its own,
the positioning means 10 comprises a rigid or semi-rigid core 15
forming the stiffening element 11, said core 15 being housed in a
sheath 16 made of flexible biocompatible material.
[0055] Thus advantageously, the positioning means 10 may take the
form of a coated needle, i.e. a composite structure in which the
stiffening element or elements are clad with a flexible and
advantageously biocompatible coating.
[0056] By way of an example, the core 15 could be made out of ABS
or polypropylene type plastic material or any other non-brittle
plastic material possessing appropriate rigidity and resistance to
strain-hardening.
[0057] According to another alternative embodiment, the core 15
could be made out of titanium, stainless steel, or any other
ductile metal that is sufficiently easy to shape in a plastic
manner, but at the same time has high stiffness and therefore a low
tendency to elastic deformation.
[0058] The sheath 16 for its part could be made out of a silicon
type elastomer, EPDM, polyurethane or any other flexible and
biocompatible material.
[0059] Besides, the positioning means 10 is preferably laid out so
that that it can be disengaged from the vicinity of the organ in a
forward motion F having the same sense as the motion by which it is
engaged around said organ in order to position the flexible band
2.
[0060] In other words, the extraction of the positioning means 10
from the operational area when said positioning means is still
beneath the skin, can advantageously be done in continuing the
movement initiated when this means was introduced into the tissues
and when the organ was circumvented, and this can be done without
its being necessary to make the positioning means 10 turn back when
it is engaged in the tissues.
[0061] Thus, the invention prevents said tissues from being
subjected to alternating stresses exposing them to risks of
wrenching and tearing.
[0062] Furthermore, such a characteristic gives the device 1 high
ergonomy, since its positioning can be done in an overall sliding
motion which corresponds to a fairly "gentle" and natural gesture
for the practitioner.
[0063] Furthermore, the positioning means 10 is preferably
connected to one of the ends 3, 4 of the flexible band 2 and
extends so as to protrude out of said flexible band 2 substantially
in the longitudinal prolongation of this band 2.
[0064] Within the meaning of the invention, the longitudinal
direction of the band corresponds to the direction that joins the
first end 3 to the second end 4 of said flexible band and
substantially follows the incurvated contour adopted by the
flexible band when it substantially matches the external wall of
the organ that it tightly binds.
[0065] More particularly, the positioning means 10 is
advantageously laid out so as to extend from the first end 3 of the
flexible band 2, beyond the internal face 21 of this band and
opposite the second end 4 of said flexible band 2.
[0066] Thus, the positioning means 10 and more particularly the
stiffening element 11 are advantageously yoked to the band,
upstream from it and in a non-overlapping manner, so as to enable
the successive engagement of the positioning means 10 and then of
the flexible band 2 in the tissues.
[0067] Preferably, the positioning means 10 is integrally situated
on only one side of the flexible band and in a particularly
preferred way at the end of this band, in a substantially centered
manner relatively to its cross-section.
[0068] More particularly, as illustrated in FIGS. 1 to 3, the
positioning means 10 can be formed by a rod 20 that extends between
a foot 21 connected to the flexible band 2 and a free head 22 which
carries the penetration means 12.
[0069] Preferably, the foot 21 is connected to the head 22 by means
of an intermediate section 23 which contains or is formed by the
stiffening element 11 in such a way that a penetration force
exerted by the foot 21 can be transmitted by said intermediate
section to the head 22 which rests against the tissues.
[0070] Thus, the positioning means 10 is advantageously designed so
as to be grasped, handled and guided by its foot 21 which forms a
sort of sleeve when the head 22, which remains free, is pushed into
the tissues.
[0071] Advantageously, the layout of the positioning means 4
according to the invention enables a practitioner in a first stage
to push the rod 20 substantially from the head 22 to the foot 21
into the tissues which surround the organ, until said head 22 is
made to emerge on the organ opposite the entry side of said rod,
and then, in a second stage, to exert a traction force on the
emerging part of the head 22 in such a way that the rod 20 is
gradually extracted from the passage that it has formed so as to be
gradually replaced by the flexible band 2, this band thus
penetrating the passage following the positioning means 10 that
precedes it.
[0072] Advantageously, the rigidity of the intermediate section 23
and of the foot 21 enables a grasping and handling of the
positioning means 10 itself but also preferably of the flexible
band 2 to which it is attached
[0073] According to one preferred embodiment illustrated in FIGS. 1
to 3, the rod 20 is cylindrical and has a circular section, which
is preferably substantially constant, giving it low traumatizing
capacity with respect to the tissues when it moves in contact with
these tissues.
[0074] Furthermore, such an arrangement gives the device 1 and its
positioning means 10 a particularly simple and compact structure
that costs little to manufacture.
[0075] According to one embodiment illustrated in FIG. 3, the
positioning means 10 forms one piece with the flexible band 2.
[0076] More particularly, the foot 21 of the rod 20 and more
particularly the sheath 16 could be shaped as one piece with a tip
30, which is advantageously cylindrical, that prolongs the flexible
band 2 and forms the end of the male locking means 5.
[0077] More particularly, the positioning means 10 has then a
preferred separation zone 31 at its junction with the flexible band
2, such as a scored zone, designed to facilitate the separation of
the positioning means 10 and the flexible band 2 after this band
has been positioned.
[0078] As shown in FIG. 3, the preferred separation zone 31 may
consist of a thinned or compressed portion forming a preferred
breaking or cut-off point enabling the practitioner to remove the
rod 20 by ablation after it has been used to introduce the flexible
band 2 around the organ.
[0079] Thus, after the device 1 has been placed and locked around
the organ, it has almost no protruding parts left and the residual
space that it occupies is particularly limited, thus restricting
the risks of post-operational complications and improving the
patient's comfort.
[0080] However, according to one preferred embodiment of the
invention, the positioning means 10 is provided with reversible
fastening means 32 designed to enable it to be alternately
connected to the device 1 and separated from the device 1 under the
practitioner's control.
[0081] In other words, the fastening means 32 advantageously give
the positioning means 10 and more particularly the rod 20 a
detachable character and give the device 1 a modular character.
[0082] Said reversible fastening means 32 could, by way of an
example, include a toothed protuberance extending the foot 21 of
the rod opposite the head 22, and intended for working together, by
a clip-on means, with a notched housing made for this purpose at
the end of the tip 30 to enable the assembling of the device 1 as
illustrated in FIGS. 1 and 2.
[0083] Advantageously, the rod 20 and more comprehensively the
positioning means 10 could thus form an outlet for a projecting
element that is adaptable at the end of the flexible band 1 and
capable of being fixed, preferably in a substantially centered
manner, in the prolongation of said flexible band 2.
[0084] In this respect, it can be noted that the invention also
pertains to the positioning means 10, detachable per se, and
especially the rod 20 provided by the core 15 and its sheath 16 and
its reversible fastening means 32.
[0085] Advantageously, it can be envisaged that the fastening means
of such a positioning means 10 will be designed in such a way that
the positioning means 10 can either be joined directly to the end
of the flexible band 2, i.e. in the tip 30 or, if the device is
provided with an inflation pouch connected to a filling catheter
designed to place said pouch in communication with a fluid
container of the implantable site type, joined to the free end of
said catheter.
[0086] Furthermore, according to another alternative embodiment, if
the device 1 is provided with a filling catheter connected to or
intended for being connected to the flexible band 2 substantially
at one of the ends of this band 2, the positioning means 10 and
more particularly the stiffening element 11 could protrude, and
preferably originate at the other, advantageously free, end of the
device 1, substantially opposite said catheter.
[0087] According to one alternative embodiment, the positioning
means 10 and more particularly the stiffening element 11 can
advantageously be mounted on or originate in proximity to that one
of the ends 3, 4 of the flexible band 2 with the smallest space
requirement, i.e. that has the transverse size or cross-section
with the smallest span, and more particularly can advantageously be
fixed to the first end 3 which bears the male element 5 of the
locking means upstream to these locking means in considering the
planned sense of the forward motion F.
[0088] Advantageously, an arrangement of this kind makes it
possible to draw along the flexible band 2 in the retro-gastric
passage in a sense of introduction that is relatively non-traumatic
i.e. in making to make it only the first end 3, which is the most
compact end and therefore the least traumatizing end, "travel"
through said retro-gastric passage during the positioning of the
device 1, while the opposite second end 4, which is bulkier,
remains withdrawn without getting engaged in said passage. Thus,
the tissues of said passage are constrained only to the precise
extent necessary and sufficient for the positioning of the
device.
[0089] Furthermore, the positioning means 10 preferably have a
cross-section smaller than that of the flexible band 2.
[0090] More particularly, the rod 20 will preferably have a
diameter smaller than the smallest overall transverse size of the
flexible band 2, as measured perpendicularly to the longitudinal
direction of this band.
[0091] Thus, the positioning means 10 do not have any excess
thickness relatively to the band in such a way that it does not
unnecessarily hollow out a tunnel that is oversized relatively to
the capacity needed to receive the flexible band.
[0092] This advantageously prevents trauma and especially
devascularization from occurring in an excessively large volume of
tissue and thus gives the device relatively low invasiveness.
[0093] Furthermore, the fact that the practitioner can use the
positioning means 10 of the invention to hollow out a passage with
a narrower section of the cross-section of the flexible band 2
advantageously enables the force-insertion of said flexible band 2
into said passage in constricting this band by a natural elastic
return of the tissues, which improves the holding of said flexible
band 2 and gives the implanted device high stability.
[0094] Naturally, the transition zone between the positioning means
10 and the flexible band 2 could advantageously comprise spreader
means 40 making it easier to spread apart the tissues that
demarcate the passage during the insertion of the flexible band
2.
[0095] In this respect, said spreader means 40 could advantageously
be constituted by the inclined faces of the pins 5 starting from
the tip 30 and forming the male locking means.
[0096] Preferably, the positioning means has a length substantially
equal to that of the stiffening element 11.
[0097] The length of the positioning means 10 and/or that of the
stiffening element 11 is furthermore preferably included between
50% and 100% of the length of the flexible band and in a
particularly preferable way included between 60% and 70% of the
length of said flexible band, the length of the flexible band being
herein considered to be the length of its contact zone, i.e.
substantially the value of the perimeter of the organ.
Advantageously, the length of the positioning means is greater than
the external semi-perimeter of the organ around which the flexible
band has to be implanted.
[0098] Furthermore, the positioning means 10, when in the
functional configuration, is preferably curved substantially
throughout its length, preferably continuously in a curvature of
the same sign.
[0099] Preferably, the positioning means is entirely situated so as
to be projecting out of the flexible band 2 and forms an extension
of invariant length relatively to this flexible band 2.
[0100] Furthermore, the external diameter of the sheath 16
preferably ranges from 2 mm to 5 mm while the diameter of the
stiffening element 1, which preferably takes the form of a rod or a
thick rope is for its part substantially between 1.5 mm and 3
mm.
[0101] Naturally, the present invention also pertains to a surgical
method for the implanting of a medical device which shall now be
described in greater detail with reference to the preferred
alternative embodiment of the device 1 illustrated in FIGS. 1 and
2.
[0102] First of all, said surgical method preferably includes a
mounting step (a) during which the practitioner integrates the
positioning means 10 into the device 1 in attaching and fixing the
rod 20, preferably by fitting in the fastening means 32 to one of
the ends 3 of the flexible band 2 or, as the case may be, to the
free end of the catheter connected to said flexible band.
[0103] Preferably, said method then comprises an adjustment step
(b) during which the practitioner elastically deforms the rod 20
and more particularly the stiffening element 11 in order to model
the positioning means 10 and give it a geometry and especially a
curvature suited to the dimensions and shape of the organ to be
treated.
[0104] To this end, the practitioner may in particular use the
plasticity of the stiffening means 11 by exerting a bending force
on the intermediate section 23 in order to curve it or on the
contrary in order to straighten it.
[0105] Advantageously, the adjusting step (b) can be done either
directly by hand or indirectly, using laparoscopy instruments, when
the device 1 is entirely beneath the skin, especially in the
abdominal cavity.
[0106] Once the desired shape has been obtained, the method
continues with an engagement step (c) during which the practitioner
makes the positioning means 10 penetrate into the tissues that are
contiguous to the organ and especially into the tissues situated
behind said organ, and causes the positioning means 10 to move
forward through said tissues so as to make it circumvent the organ
until the head 22 emerges from said tissues substantially opposite
the side by which the positioning means 10 is introduced relatively
to the organ.
[0107] To this end, the practitioner can advantageously grasp the
rod 20 by its foot 21 and exert a thrust force on said rod that is
transmitted to the head 22 by the intermediate section 23 so that
the head 22 compresses the tissues and forces a passage through
these tissues in a forward movement F.
[0108] Advantageously, the engagement step (c) is simultaneously
accompanied by a perforation sub-step (c1) during which the
practitioner pierces and separates the tissues situated before the
head 22 by means of the penetration means 12 in the sense of the
forward motion F as and when the rod 20 moves forward in order to
clear a passage in the mass of tissue.
[0109] In other words, the practitioner can advantageously
introduce the positioning means 10 directly by force into the
tissues in order to draw said positioning means around the organ
and if necessary guide it along feeling his way around.
[0110] Advantageously, the rigidity of the stiffening element
enables it to lastingly maintain the conformation of the
positioning means 10 chosen by the practitioner, especially to
counter the buckling forces resulting from the resistance to
penetration put up against it by the tissues.
[0111] Once the free end of the positioning means 10, i.e. the head
22, has emerged from the tissues, i.e. once the organ has been
"hooked", the practitioner can visually ascertain that the position
of the positioning means relatively to the organ substantially
corresponds to the configuration in which he wishes to place the
flexible band around said organ.
[0112] Advantageously, the length of the positioning means 10 is
sufficient for this means to substantially mark out the entire path
for placing the flexible band around the concealed, portion i.e.
the non-apparent portion, of the perimeter of the organ.
[0113] If necessary, the practitioner can maneuver the positioning
means or even make it take the return path at least partly in order
to then reintroduce it around the organ and bring it, by iteration,
to a position that he considers to be appropriate.
[0114] The practitioner then performs a step (d) of extraction
during which he grasps the positioning means 10, for example by
gripping the emerging head 22 by means of a clamp, and then exerts
a traction force on said positioning means 10 so as to gradually
withdraw it from the tissues, in a motion that is in the same sense
as the forward motion F which had enabled the insertion of the
positioning means 10.
[0115] Advantageously, the extraction of the positioning means 10
prompts a mechanical pull on the rest of the device 1 by traction
on the end of the flexible band 2, either directly at the tip 30 or
indirectly at the catheter which acts like a traction cable.
[0116] Under the effect of this traction, the flexible band 2
appears at the entry to the passage hollowed out by the positioning
means into which it penetrates, the spreader means 40 deforming
said passage to widen it and facilitate the progress in succession
of the rest of the flexible band 2.
[0117] Said flexible band 2 is thus drawn by the positioning means
10 and guided by the passage in the wake of said positioning means
until it has substantially gone around the organ and until its
first end 3 emerges from the passage.
[0118] The extraction step (d) is thus accompanied by a sub-step in
which the flexible band 2 is gradually substituted for the
positioning means 10 in the passage preformed by this positioning
means 10.
[0119] Advantageously, the second end 4 of the flexible band 2 is
not engaged in the passage and remains constantly emergent on the
side of the organ where said band had been introduced.
[0120] The practitioner can then proceed to a separation step (e)
during which he disconnects and moves the positioning means 10 away
from the device 1 and more particularly from the flexible band 2 in
unlocking the fastening means 32 or, as the case may be, in
sectioning the junction between the positioning means 10 and the
flexible band 2 at the preferred separation zone 31.
[0121] Advantageously, the flexible band 2 is held by itself in
place around the organ during this separation step, through the
elastic stress exerted on it by the tissues which constitute the
wall of the passage, said flexible band 2 being thus sheathed by a
natural and vascularized sleeve of tissue.
[0122] Besides, before the separation step (e) the practitioner can
use the positioning means 10 and more particularly thread them into
the sleeve forming the is female locking means 6 in order to engage
the male locking means 5 into this female locking means and thus
form the device 1 by locking it into position around the organ.
[0123] When the positioning means is fixed to the catheter, it can
then be disconnected from the catheter and replaced by the
implantable site.
[0124] Naturally, this step for closing the ring could also be
achieved, as the case may be, after the separation step (e).
[0125] Thus, the implantable medical device of the invention
advantageously forms an autonomous device which can be positioned
simply and reliably by its own means requiring a minimum number of
surgical gestures, thus reducing the difficulty, time and risks of
the operation.
[0126] Furthermore, the device 1 according to the invention
advantageously has a simple, compact and substantially
non-traumatic structure.
* * * * *